EscaBoi

Anyone else notice the average fuel economy in Acura's trip computer is not very accurate? I've noticed this also on my TSX.

I track my mileage on gasprices.com and notice the trip computer also shows better than actual. For example my last trip I actually averaged 12.4L/100km. The trip computer says it was 11.7L/100km.

I've always wondered why this is?

Lanesky_OH8RDX

in the car the meter runs off of injector duty, speed, rpm, air density and throttle position and gives an average. I can honestly tell you that the car is more accurate than the website because the car is taking in many many factors all at once instead of just punching numbers into a website that wont think of the air temperature, hills, throttle position etc. That's my opinion anyways. I drove from Vancouver to Halifax and to get and I used my trip meter. I found it quite accurate.

Mr Marco

OP,
there are several threads already on the subject...SEARCH FIRST

https://acurazine.com/forums/1g-rdx-2007-2012-147/what-fuel-economy-you-getting-680401/

https://acurazine.com/forums/1g-rdx-2007-2012-147/trip-computer-accuracy-826467/

etc

Slow98teg

I've never gone off of what any car says. I do it the old fashion way. Fill up, run it low, fill back up and divide total miles by gallons.

EscaBoi

Those threads don't really answer my question, since I was wondering why it isn't so accurate. But anyways, seems most people seem to find it quite accurate.

However, in my instance I calculate my gas mileage manually (liters filled divided by kilometers) and it doesn't equal to what the trip computer shows. The reason why I ask is because my TSX has been the same for the 5 years I've owned it and notice the same thing is happening with the RDX.

Example, my last fill up was 24.468 liters and I got 177km out of it, so my average was 13.8L/100km. The trip computer showed I was getting 12.8L/100km during that time. Which is totally off.

pickler

it's not accurate on any car. A trip computer gauge works either with a MAF (volume) sensor or a MAP (pressure) sensor. It estimates mileage based on either of those factors. nothing can ever really accurately measure fuel mileage because there are so many factors involved. Even taking injector pulse width into account doesn't mean anything because fuel pressure can change and that actually affects how much fuel is injected. it's all an estimate. Get a scangauge 2 and calibrate it a few times. It will become within 1% accurate over time as it learns about your engine.

ps. our cars only estimate mileage using the MAF sensor, i think only information retrieved from injectors is if it's firing (to take fuel injector cut off during coasting in to equation). MAF scaling can also improve mileage accuracy, fuel economy and power...but i'm not sure if there are any tools for that for Acuras.